Production of olefin dimers and oligomers

ABSTRACT

Disclosed is an olefin containing stream from an oxygenate to olefin process, and a process for making olefin dimer and oligomer product from the olefin containing stream using a nickel based oligomerization catalyst. The dimer/oligomer product is optionally converted to hydroformylated product. The olefin containing stream that is used to make the higher olefin product has low levels of impurities including nitrogen, sulfur and/or chlorine.

[0001] This Application is a Continuation-in-Part of U.S. ProvisionalApplication Serial No. 60/265,700, filed Feb. 1, 2001, which isincorporated by reference herein.

FIELD OF THE INVENTION

[0002] This invention relates to an olefin stream and a method of makingand using the olefin stream. In particular, the invention relates todimerizing or oligomerizing an olefin stream using a nickel basedcatalyst, and optionally, hydroformylating the dimerized or oligomerizedolefin stream.

BACKGROUND OF THE INVENTION

[0003] Olefin streams containing predominantly C₃ to C₅ olefins havebeen used as feed for oligomerization units. Such units are particularlyuseful for forming dimers as well as oligomers, the terms dimer andoligomer being used interchangeably herein. The dimers and oligomers canbe converted to a variety of alkanes, aldehydes, alcohols and acids.

[0004] The formation of the dimers or oligomers is conventionallyaccomplished by catalytic reaction. Catalysts used in the reaction aretypically nickel based catalysts or acid type catalysts.

[0005] Cosyns, J. et al., in “Process for upgrading C3, C4 and C5olefinic streams,” Pet. & Coal, Vol. 37, No. 4 (1995), describe a nickelbased catalyst system known as the Dimersol® process. This process isuseful for dimerizing or oligomerizing a variety of olefin feeds. Inparticular, the process is useful for dimerizing or oligomerizingpropylene, butylene and pentylene streams.

[0006] U.S. Pat. No. 6,049,017 to Vora et al., describes thedimerization of a predominantly n-butylene containing feed stream. Then-butylene feed stream is ultimately derived from an olefin streamcontaining a variety of butylenes produced by a methanol to olefinsreaction unit. The butylene stream from the methanol to olefins unit ispretreated by a combination of partial hydrogenation of dienes andisobutylene removal by way of an MTBE process, before sending theresulting n-butylene stream to the dimerization unit.

[0007] Nickel based catalysts, such as that described by Cosyns, areparticularly good for obtaining dimers having a low degree of branching.However, these catalysts are particularly sensitive to deactivation bysulfur, nitrogen, and chlorine atoms. Since these atoms are commonlypresent in a variety of compounds in untreated olefin feed streams, thefeed streams require a substantial amount of treatment in order toremove the poisonous sulfur, nitrogen and chlorine containing compounds.

[0008] Dimers and/or oligomers which are mono-olefins, and have a lowdegree of branching are highly preferred. Low branching can beconsidered a combination of both normal olefins and mono-branchedolefins, particularly mono-methyl branched olefins. However, as shown inVora, the preferred dimers and/or oligomers are conventionally obtainedonly after significant pretreatment of the olefin feed stream.

[0009] As the prior art references have shown, conventional methods ofdimerizing and/or oligomerizing olefin feed stream to obtain desirableproducts have required a significant amount of pretreatment. It isdesirable, therefore, to reduce the amount of required pretreatmentwithout sacrificing the linear quality of the dimer and/or oligomerproduct.

SUMMARY OF THE INVENTION

[0010] This invention provides a method for obtaining a dimerized oroligomerized olefin product without using a significant amount of feedpretreatment. The product can be obtained without having to useadditional means of hydrogenation or isoolefin removal, yet maintainingrelatively low branching characteristics. The dimerized or oligomerizedproduct is optionally converted to a hydroformylated product.

[0011] Specifically, the invention is directed to a method of dimerizingor oligomerizing an olefin which comprises contacting oxygenate with anolefin forming catalyst to form an olefin product. A propylene, butyleneor pentylene containing stream is separated from the olefin productwhich contains at least 50 wt. % propylene, butylene, pentylene, or acombination thereof, and the separated olefin stream contains notgreater than 1 ppm by weight sulfur calculated on an atomic basis and0.5 to 10 wt. % isoolefin. The separated olefin stream is contacted witha nickel based oligomerization catalyst to form a dimer or oligomerproduct.

[0012] In another embodiment the foregoing method is followed, exceptthe olefin forming catalyst is a silicoaluminophosphate catalyst.

[0013] In another embodiment, the separated olefin stream comprises notgreater than 1 ppm by weight nitrogen. In yet another embodiment, theseparated olefin stream comprises not greater than 0.5 ppm by weightchlorine. In still another embodiment, the isoolefin is isobutylene.

[0014] The silicoaluminophosphate catalyst, according to one embodiment,is made from SAPO-34 or SAPO-18 molecular sieves, or a combinationthereof. Preferably, the silicoaluminophosphate is an intergrowth ofSAPO-34 and SAPO-18 or ALPO-18.

[0015] According to one embodiment, the dimer or oligomer product isrecovered and contacted with a hydroformylating catalyst to form ahydroformylated product. According to another embodiment, thehydroformylated product is converted to an acid or alcohol.Alternatively, the acid or alcohol is converted to an ester, if desired.The ester is optionally added to a polymer composition.

[0016] The invention is also directed to an olefin composition. Thecomposition, according to one embodiment, comprises at least 50 wt. %propylene, butylene, pentylene or a combination thereof, and containsnot greater than 1 ppm by weight sulfur, not greater than 1 ppm byweight nitrogen, and not greater than 0.5 ppm by weight chlorine, eachcalculated on an atomic basis, and 0.5 to 10 wt. % isoolefin. Theisoolefin is preferably isobutylene.

[0017] The invention further provides a method of converting anoxygenate to a hydroformylated product. The method comprises contactingoxygenate with a silicoaluminophosphate molecular sieve catalyst to forman olefin product, and separating a propylene, butylene or pentylenecontaining olefin stream from the olefin product, wherein the separatedolefin stream comprises at least 50 wt. % propylene, butylene,pentylene, or a combination thereof, and the separated olefin streamcontains not greater than 1 ppm by weight sulfur calculated on an atomicbasis, and 0.5 to 10 wt. % isoolefin. The separated olefin stream iscontacted with a nickel based oligomerization catalyst to form a dimeror oligomer product; and the dimer or oligomer product is contacted witha hydroformylating catalyst to form a hydroformylated product.

DETAILED DESCRIPTION OF THE INVENTION

[0018] According to this invention, desirable dimerized or oligomerizedolefin product is obtained by providing an olefin feed stream that ispredominantly derived from an oxygenate to olefins unit. Such a feedstream should be low in sulfur, nitrogen and chlorine content, to theextent that no or essentially no pretreatment will be required forremoval of such components.

[0019] In order to obtain a product having an acceptable degree oflinearity, a nickel based catalyst system is to be used. Such a systemprovides a highly linear dimer or oligomer product, without requiringisoolefin removal from the feed stream. If desired, olefin made fromcracking a hydrocarbon stream is added to the olefin feed made from theoxygenate, according to one embodiment, as long as the total isoolefincontent of the feed is not too high.

[0020] Desirably, the olefin feed stream is obtained by contactingoxygenate with a molecular sieve catalyst. The oxygenate comprises atleast one organic compound which contains at least one oxygen atom, suchas aliphatic alcohols, ethers, carbonyl compounds (aldehydes, ketones,carboxylic acids, carbonates, esters and the like). When the oxygenateis an alcohol, the alcohol includes an aliphatic moiety having from 1 to10 carbon atoms, more preferably from 1 to 4 carbon atoms.Representative alcohols include but are not necessarily limited to lowerstraight and branched chain aliphatic alcohols and their unsaturatedcounterparts. Examples of suitable oxygenate compounds include, but arenot limited to: methanol; ethanol; n-propanol; isopropanol; C₄-C₂₀alcohols; methyl ethyl ether; dimethyl ether; diethyl ether;di-isopropyl ether; formaldehyde; dimethyl carbonate; dimethyl ketone;acetic acid; and mixtures thereof. Preferred oxygenate compounds aremethanol, dimethyl ether, or a mixture thereof.

[0021] The molecular sieve catalyst used in this invention is anoxygenate to olefin catalyst, which is defined as any molecular sievecapable of converting an oxygenate to an olefin compound. Such molecularsieves include zeolites as well as non-zeolites, and are of the large,medium or small pore type. Small pore molecular sieves are preferred inone embodiment of this invention, however. As defined herein, small poremolecular sieves have a pore size of less than about 5.0 Angstroms.Generally, suitable catalysts have a pore size ranging from about 3.5 toabout 5.0 angstroms, preferably from about 4.0 to about 5.0 Angstroms,and most preferably from about 4.3 to about 5.0 Angstroms.

[0022] Zeolite materials, both natural and synthetic, have beendemonstrated to have catalytic properties for various types ofhydrocarbon conversion processes. In addition, zeolite materials havebeen used as adsorbents, catalyst carriers for various types ofhydrocarbon conversion processes, and other applications. Zeolites arecomplex crystalline aluminosilicates which form a network of AlO₂ ⁻ andSiO₂ tetrahedra linked by shared oxygen atoms. The negativity of thetetrahedra is balanced by the inclusion of cations such as alkali oralkaline earth metal ions. In the manufacture of some zeolites,non-metallic cations, such as tetramethylammonium (TMA) ortetrapropylammonium (TPA), are present during synthesis. Theinterstitial spaces or channels formed by the crystalline network enablezeolites to be used as molecular sieves in separation processes, ascatalyst for chemical reactions, and as catalyst carriers in a widevariety of hydrocarbon conversion processes.

[0023] Zeolites include materials containing silica and optionallyalumina, and materials in which the silica and alumina portions havebeen replaced in whole or in part with other oxides. For example,germanium oxide, tin oxide, and mixtures thereof can replace the silicaportion. Boron oxide, iron oxide, gallium oxide, indium oxide, andmixtures thereof can replace the alumina portion. Unless otherwisespecified, the terms “zeolite” and “zeolite material” as used herein,shall mean not only materials containing silicon atoms and, optionally,aluminum atoms in the crystalline lattice structure thereof, but alsomaterials which contain suitable replacement atoms for such silicon andaluminum atoms.

[0024] One preferred type of olefin forming catalyst useful in thisinvention is one containing a silicoaluminophosphate (SAPO) molecularsieve. Silicoaluminophosphate molecular sieves are generally classifiedas being microporous materials having 8, 10, or 12 membered ringstructures. These ring structures can have an average pore size rangingfrom about 3.5 to about 15 angstroms. Preferred are the small pore SAPOmolecular sieves having an average pore size of less than about 5angstroms, preferably an average pore size ranging from about 3.5 toabout 5 angstroms, more preferably from about 3.5 to about 4.2angstroms. These pore sizes are typical of molecular sieves having 8membered rings.

[0025] According to one embodiment, substituted SAPOs can also be usedin oxygenate to olefin reaction processes. These compounds are generallyknown as MeAPSOs or metal-containing silicoaluminophosphates. The metalcan be alkali metal ions (Group IA), alkaline earth metal ions (GroupIIA), rare earth ions (Group IIIB, including the lanthanoid elements:lanthanum, cerium, praseodymium, neodymium, samarium, europium,gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium andlutetium; and scandium or yttrium) and the additional transition cationsof Groups IVB, VB, VIB, VIIB, VIIIB, and IB.

[0026] Preferably, the Me represents atoms such as Zn, Mg, Mn, Co, Ni,Ga, Fe, Ti, Zr, Ge, Sn, and Cr. These atoms can be inserted into thetetrahedral framework through a [MeO₂] tetrahedral unit. The [MeO₂]tetrahedral unit carries a net electric charge depending on the valencestate of the metal substituent. When the metal component has a valencestate of +2, +3, +4, +5, or +6, the net electric charge is between −2and +2. Incorporation of the metal component is typically accomplishedadding the metal component during synthesis of the molecular sieve.However, post-synthesis ion exchange can also be used. In post synthesisexchange, the metal component will introduce cations into ion-exchangepositions at an open surface of the molecular sieve, not into theframework itself.

[0027] Suitable silicoaluminophosphate molecular sieves include SAPO-5,SAPO-8, SAPO-11, SAPO-16, SAPO-17, SAPO-18, SAPO-20, SAPO-31, SAPO 34,SAPO-35, SAPO-36, SAPO-37, SAPO-40, SAPO-41, SAPO-42, SAPO-44, SAPO-47,SAPO-56, the metal containing forms thereof, and mixtures thereof.Preferred are SAPO-18, SAPO-34, SAPO-35, SAPO-44, and SAPO-47,particularly SAPO-18 and SAPO-34, including the metal containing formsthereof, and mixtures thereof. As used herein, the term mixture issynonymous with combination and is considered a composition of matterhaving two or more components in varying proportions, regardless oftheir physical state.

[0028] An aluminophosphate (ALPO) molecular sieve can also be includedin the catalyst composition. Aluminophosphate molecular sieves arecrystalline microporous oxides which can have an AIPO₄ framework. Theycan have additional elements within the framework, typically haveuniform pore dimensions ranging from about 3 angstroms to about 10angstroms, and are capable of making size selective separations ofmolecular species. More than two dozen structure types have beenreported, including zeolite topological analogues. A more detaileddescription of the background and synthesis of aluminophosphates isfound in U.S. Pat. No. 4,310,440, which is incorporated herein byreference in its entirety. Preferred ALPO structures are ALPO-5,ALPO-11, ALPO-18, ALPO-31, ALPO-34, ALPO-36, ALPO-37, and ALPO-46.

[0029] The ALPOs can also include a metal substituent in its framework.Preferably, the metal is selected from the group consisting ofmagnesium, manganese, zinc, cobalt, and mixtures thereof. Thesematerials preferably exhibit adsorption, ion-exchange and/or catalyticproperties similar to aluminosilicate, aluminophosphate and silicaaluminophosphate molecular sieve compositions. Members of this class andtheir preparation are described in U.S. Pat. No. 4,567,029, incorporatedherein by reference in its entirety.

[0030] The metal containing ALPOs have a three-dimensional microporouscrystal framework structure of Mo₂, AlO₂ and PO₂ tetrahedral units.These as manufactured structures (which contain template prior tocalcination) can be represented by empirical chemical composition, on ananhydrous basis, as:

mR: (M_(x)Al_(y)P_(z))O₂

[0031] wherein “R” represents at least one organic templating agentpresent in the intracrystalline pore system; “m” represents the moles of“R” present per mole of (M_(x)Al_(y)P_(z))O₂ and has a value of fromzero to 0.3, the maximum value in each case depending upon the moleculardimensions of the templating agent and the available void volume of thepore system of the particular metal aluminophosphate involved, “x”, “y”,and “z” represent the mole fractions of the metal “M”, (i.e. magnesium,manganese, zinc and cobalt), aluminum and phosphorus, respectively,present as tetrahedral oxides.

[0032] The metal containing ALPOs are sometimes referred to by theacronym as MeAPO. Also in those cases where the metal “Me” in thecomposition is magnesium, the acronym MAPO is applied to thecomposition. Similarly ZAPO, MnAPO and CoAPO are applied to thecompositions which contain zinc, manganese and cobalt respectively. Toidentify the various structural species which make up each of thesubgeneric classes MAPO, ZAPO, CoAPO and MnAPO, each species is assigneda number and is identified, for example, as ZAPO-5, MAPO-11, CoAPO-34and so forth.

[0033] The silicoaluminophosphate molecular sieve is typically admixed(i.e., blended) with other materials. When blended, the resultingcomposition is typically referred to as a SAPO catalyst, with thecatalyst comprising the SAPO molecular sieve.

[0034] Materials which can be blended with the molecular sieve can bevarious inert or catalytically active materials, or various bindermaterials. These materials include compositions such as kaolin and otherclays, various forms of rare earth metals, metal oxides, othernon-zeolite catalyst components, zeolite catalyst components, alumina oralumina sol, titania, zirconia, magnesia, thoria, beryllia, quartz,silica or silica or silica sol, and mixtures thereof. These componentsare also effective in reducing, inter alia, overall catalyst cost,acting as a thermal sink to assist in heat shielding the catalyst duringregeneration, densifying the catalyst and increasing catalyst strength.It is particularly desirable that the inert materials that are used inthe catalyst to act as a thermal sink have a heat capacity of from about0.05 to about 1 cal/g-° C., more preferably from about 0.1 to about 0.8cal/g-° C., most preferably from about 0.1 to about 0.5 cal/g-° C.

[0035] Additional molecular sieve materials can be included as a part ofthe SAPO catalyst composition or they can be used as separate molecularsieve catalysts in admixture with the SAPO catalyst if desired.Structural types of small pore molecular sieves that are suitable foruse in this invention include AEI, AFT, APC, ATN, ATT, ATV, AWW, BIK,CAS, CHA, CHI, DAC, DDR, EDI, ERI, GOO, KFI, LEV, LOV, LTA, MON, PAU,PHI, RHO, ROG, THO, and substituted forms thereof. Structural types ofmedium pore molecular sieves that are suitable for use in this inventioninclude MFI, MEL, MTW, EUO, MTT, HEU, FER, AFO, AEL, TON, andsubstituted forms thereof. These small and medium pore molecular sievesare described in greater detail in the Atlas of Zeolite StructuralTypes, W. M. Meier and D. H. Olsen, Butterworth Heineman, 3rd ed., 1997,the detailed description of which is explicitly incorporated herein byreference. Preferred molecular sieves which can be combined with asilicoaluminophosphate catalyst include ZSM-5, ZSM-34, erionite, andchabazite.

[0036] The catalyst composition, according to an embodiment, preferablycomprises from about 1% to about 99%, more preferably from about 5% toabout 90%, and most preferably from about 10% to about 80%, by weight ofmolecular sieve. It is also preferred that the catalyst composition havea particle size of from about 20 microns to about 3,000 microns, morepreferably from about 30 microns to about 200 microns, most preferablyfrom about 50 microns to about 150 microns.

[0037] The catalyst can be subjected to a variety of treatments toachieve the desired physical and chemical characteristics. Suchtreatments include, but are not necessarily limited to hydrothermaltreatment, calcination, acid treatment, base treatment, milling, ballmilling, grinding, spray drying, and combinations thereof.

[0038] A preferred catalyst of this invention is a catalyst whichcontains a combination of SAPO-34, and SAPO-18 or ALPO-18 molecularsieve. In a particularly preferred embodiment, the molecular sieve is acrystalline intergrowth of SAPO-34, and SAPO-18 or ALPO-18.

[0039] To convert oxygenate to olefin for use as olefin feed,conventional reactor systems can be used, including fixed bed, fluid bedor moving bed systems. Preferred reactors of one embodiment areco-current riser reactors and short contact time, countercurrentfree-fall reactors. Desirably, the reactor is one in which an oxygenatefeedstock can be contacted with a molecular sieve catalyst at a weighthourly space velocity (WHSV) of at least about 1 hr⁻¹, preferably in therange of from about 1 hr⁻¹ to 1000 hr⁻¹, more preferably in the range offrom about 20 hr⁻¹to about 1000 hr⁻¹, and most preferably in the rangeof from about 20 hr⁻¹ to about 500 hr⁻¹. WHSV is defined herein as theweight of oxygenate, and hydrocarbon which may optionally be in thefeed, per hour per weight of the molecular sieve content of thecatalyst. Because the catalyst or the feedstock may contain othermaterials which act as inerts or diluents, the WHSV is calculated on theweight basis of the oxygenate feed, and any hydrocarbon which may bepresent, and the molecular sieve contained in the catalyst.

[0040] Preferably, the oxygenate feed is contacted with the catalystwhen the oxygenate is in a vapor phase. Alternately, the process may becarried out in a liquid or a mixed vapor/liquid phase. When the processis carried out in a liquid phase or a mixed vapor/liquid phase,different conversions and selectivities of feed-to-product may resultdepending upon the catalyst and reaction conditions.

[0041] The process can generally be carried out at a wide range oftemperatures. An effective operating temperature range can be from about200° C. to about 700° C., preferably from about 300° C. to about 600°C., more preferably from about 350° C. to about 550° C. At the lower endof the temperature range, the formation of the desired olefin productsmay become markedly slow. At the upper end of the temperature range, theprocess may not form an optimum amount of product.

[0042] Olefins obtained by cracking hydrocarbon streams can also be usedto form the olefin feed stream of this invention. It is preferable,however, that such olefins be combined with the olefin product of theoxygenate conversion reaction. This is because the olefins obtained by acracking process are generally high in non-reactive hydrocarboncomponents such as alkanes, are high in branchiness, and are high inother undesirable by-products such as sulfur, which can cause conversionproblems in the higher olefin reaction process. Therefore, additionalpurification of such a stream would be needed.

[0043] Conventional processes for removing water, oxygenates and otherundesirable components from hydrocarbon streams can be used to obtainthe olefin feed stream of this invention. Such methods include waterwashing, caustic scrubbing, distillation, and fixed bed adsorption.Other desirable methods, such as those found in Kirk-Othmer Encyclopediaof Chemical Technology, 4th edition, Volume 9, John Wiley & Sons, 1996,pg. 894-899, the description of which is incorporated herein byreference, can also be used. In addition, purification systems such asthat found in Kirk-Othmer Encyclopedia of Chemical Technology, 4thedition, Volume 20, John Wiley & Sons, 1996, pg. 249-271, thedescription of which is also incorporated herein by reference, can beused.

[0044] The olefin feed of this invention has a substantially reducedsulfur, nitrogen and/or chlorine content. According to one embodiment,the olefin feed also contains isoolefin at a concentration that does notsubstantially adversely affect the linear quality of dimerized oroligomerized product. Such product contains enough n-olefin andmono-branched mono-olefin to provide derivative products, particularlyesters, that are highly desirable for industrial end uses. Esterderivatives from the dimer and oligomer products of this invention willbe particularly suitable for use as plasticizers.

[0045] The sulfur content of the olefin feed of this invention should besufficiently low such that the activity of the catalyst used to form theolefin dimer or oligomer is not substantially inhibited. Preferably, thesulfur content in the olefin feed is not greater than about 1 ppm; morepreferably, not greater than about 0.5 ppm; and most preferably, notgreater than about 0.3 ppm by weight, calculated on an atomic basis.

[0046] The nitrogen content of the olefin feed of this invention shouldalso be sufficiently low such that the catalytic activity of thecatalyst used to form the olefin dimer or oligomer is not substantiallyinhibited. Preferably, the nitrogen content in the olefin feed is notgreater than about 1 ppm; more preferably, not greater than about 0.5ppm; and most preferably, not greater than about 0.3 ppm by weight,calculated on an atomic basis.

[0047] The chlorine content of the olefin feed of this invention shouldalso be sufficiently low such that the catalytic activity of thecatalyst used to form the olefin dimer or oligomer is not substantiallyinhibited. Preferably, the chlorine content in the olefin feed is notgreater than about 0.5 ppm; more preferably, not greater than about 0.4ppm; and most preferably, not greater than about 0.3 ppm by weight,calculated on an atomic basis.

[0048] In this invention, a nickel based oligomerization catalyst isused to provide a dimer or oligomer product. This allows for the olefinfeed to contain a substantial amount of isoolefin compared toconventional processing requirements. According to this invention, theolefin feed can contain from about 0.5 to about 10 wt. % isoolefin.Preferably the olefin feed contains from about 1 to about 8 wt. %isoolefin, more preferably about 2 to about 6 wt. % isoolefin.Preferably, the isoolefin is isobutylene.

[0049] Particularly preferred in an embodiment of this invention is amono-olefin feed stream comprising a major amount of propylene,butylene, pentylene, or a combination thereof. Preferably, the feedstream comprises at least about 50 wt. % propylene, butylene, pentylene,or a combination thereof, more preferably at least about 60 wt. %propylene, butylene, pentylene, or a combination thereof, and mostpreferably at least about 70 wt. % propylene, butylene, pentylene, or acombination thereof.

[0050] It is also desirable, according to one embodiment, that theolefin feed stream of this invention be high in linear mono-olefincontent so as to maintain a sufficiently high conversion to higherolefin product having few branches. Preferably, the olefin feed streamcomprises at least about 50 wt. % linear monoolefin, more preferably atleast about 60 wt. % linear mono-olefin; and most preferably at leastabout 70 wt. % linear mono-olefin. Preferably, the linear monoolefin isa C₂ to C₅ linear mono-olefin and has a C₆ and higher hydrocarboncontent of not greater than about 20 wt. %; more preferably, not greaterthan about 15 wt. %; and most preferably, not greater than about 10 wt.%

[0051] The olefin feed streams of this invention are contacted withnickel based oligomerization catalysts in order to form desirable dimerand/or oligomer products. As used herein, dimerization andoligomerization processes are considered interchangeable terms. Theprocesses are also known as higher olefins processes. Dimerizationprocesses, oligomerization processes and higher olefins formingprocesses are all phrases that define the dimerization and/oroligomerization of light olefins, particularly C₂-C₅ olefins, to form adimer or oligomer product, the product also referred to as a higherolefin. Examples of commercially available nickel-based catalysts usedin these processes include but are not limited to Dimersol®, OCTOL® andSHOP® catalysts.

[0052] The Dimersol® process is used to oligomerize olefins with solublenickel complexes. These complexes are described in greater detail byYves Chauvin, Helene Olivier; in Applied Homogeneous Catalysts withOrganometallic Compounds; edited by Boy Comils, Wolfgang A. Herrmann;Verlag Chemie, 1996, 258-268, incorporated herein by reference.

[0053] The Dimersol® process, according to one embodiment, can becarried out at a temperature ranging from about 50° C. to about 80° C.and a pressure ranging from about 1600 kPa to about 1800 kPa in a liquidphase. The catalyst is made from a catalyst precursor mixture containinga nickel salt and an aluminum based co-catalyst. The two componentsproduce a working Ziegler nickel hydride catalyst. The catalystcomponents are injected separately into a reaction loop. Ammonia andwater are used to neutralize the catalyst in the reaction system, andhigher olefin product is separated from an aqueous phase in the reactor.The catalyst can then be recovered and recycled.

[0054] The OCTOL® process is a fixed-bed nickel catalyst system, and isused by OXENO OLEFINCHEMIE GmbH. The process is described in relativedetail in Hydrocarbon Process., Int. Ed. (1986) 65, 2, Sect. 1, 31-33,which is incorporated herein by reference.

[0055] Another nickel based oligomerization catalyst system is the ShellHigher Olefin Process (SHOP). The SHOP catalyst is produced in situ froma nickel salt, such as nickel chloride, sodium borohydride, and achelating ligand. Suitable ligands are compounds of the general formulaRR¹P—CH₂—COR². Examples of the ligand include diphenyl phosphinoaceticacid, dicyclohexyl-phosphinoaceticd acid, and9-(carboxymethyl)-9-phosphabicyclo[3.3.1]-nonane. The oligomerizationreaction can be carried out at a temperature ranging from about 80 toabout 120° C. and a pressure ranging from about 7 to about 14 MPa.

[0056] In another embodiment of a nickel-based catalyst system,oligomerization of the olefin feed stream can be carried out in thepresence of a nickel oxide (NiO) catalyst such as that described in U.S.Pat. No. 5,254,783 to Saleh et al., the description of which isincorporated herein by reference. The catalyst contains amorphous NiOpresent as a disperse monolayer on the surface of a silica support. Thecatalyst desirably has a support which contains minor amounts of anoxide of aluminum, gallium or indium such that the ratio of NiO to metaloxide present in the catalyst is within the range of from about 4:1 toabout 100:1.

[0057] Oligomerization using a NiO catalyst is desirably carried out inthe liquid phase at temperature ranging from about 150° C. to about 275°C. A hourly weight feed rate of butene over the catalyst of from about0.4 hr⁻¹ to about 1.8 hr⁻¹, preferably from about 0.6 hr⁻¹ to about 0.7hr⁻¹is preferred according to this embodiment. It is also preferred thata ratio of olefin to catalyst be from about 2:1 to about 8:1, morepreferably from about 4:1 to about 6:1.

[0058] Another embodiment of a nickel based catalyst is a hydrocarbonsoluble nickel carboxylate. In this embodiment, at least one inorganiccompound of divalent nickel interacts with a halogenoacetic acid. Thenickel inorganic compound can be a carbonate, a bicarbonate, a basiccarbonate (hydroxycarbonate), a hydroxide or an oxide. thehalogenoacetic acid can be monochloroacetic, monofluoroacetic,dichloroacetic, tricholoracetic, difluoroacetic or trifluoroacetic. Thistype of catalyst is described in greater detail in U.S. Pat. No.4,716,239, the description of which is incorporated herein by reference.

[0059] Another embodiment of a nickel based oligomerization catalyst isone that is made by mixing together a liquid mixture of at least onelithium halide with at least one hydrocarbylaluminum halide and acatalytic nickel containing mixture. The nickel mixture can bezerovalent, monovalent, or divalent complexes. This type of catalyst isdescribed in greater detail in U.S. Pat. No. 5,723,712, the descriptionof which is incorporated herein by reference.

[0060] Following the oligomerization reaction, the higher olefin productis optionally recovered, and further converted to desirable derivativeproducts. These derivative products can be paraffin mixtures, obtainedby conventional hydrogenation processes and optional blending and/oradditional distillation. The paraffin mixtures can be used ashydrocarbon fluids and/or solvents in many applications, includingpaints and coatings, process fluids, metal cleaning, dry cleaning,cosmetics, pharmaceuticals, agrochemicals, degreasing, aerosolpropellants, adhesives, cleaners, inks, and other industrial andhousehold products.

[0061] Other higher olefins derivatives include thiols (often calledmercaptans) or sulfides, which are produced by reacting with a sulfurcompound. These are valuable starting materials for agriculturalchemicals, pharmaceuticals, cosmetic ingredients, antioxidants,fragrance components and polysulfides. They are also used aspolymerization regulators in rubber and plastics manufacture.

[0062] Examples of other derivatives include alkylated aromatics, usingconventional alkylation processes. The alkylated aromatics can befurther processed to their lubricant components or surfactantderivatives, or used as a hydrocarbon fluid as is.

[0063] A particularly desirable conversion process for higher olefins iscarbonylation in general or hydroformylation in particular. Theseprocesses lead to various derivatives, including esters, aldehydes, andalcohols. An overview of catalysts and reaction conditions ofhydroformylation processes is given for example by Beller et al. inJournal of Molecular Catalysis, A104 (1995), pages 17-85, the details ofwhich are incorporated herein by reference. See also UllmannsEncyclopedia of Industrial Chemistry, Vol. A5 (1986), pages 217 to 233;which is also incorporated herein by reference. Further description isfound in J. Falbe, Carbon Monoxide in Organic Synthesis, 1967; and J.Falbe, New Synthesis with Carbon Monoxide, 1980.

[0064] Hydroformylation involves the contacting of the higher olefinproduct, carbon monoxide and hydrogen with the hydroformylation catalystor its precursor. Hydroformylation catalysts are organometalliccomplexes of the metals of Group VIII of the periodic system, optionallyused in combination as bi- or tri-metallic systems, and optionally withsalts of other metals as promoters, for example tin chloride. Thecatalytic organometallic complexes are combinations of catalytic metalswith various ligands. Preferred metals are cobalt, rhodium andpalladium.

[0065] The organometallic catalyst can be introduced as the activeorganometallic complex, or the complexes can be made in situ fromcatalyst precursors and ligands introduced into a reaction zone.Suitable catalyst precursors include, for example, the respective metalhydrides, halides, nitrates, sulfates, oxides, sulfides and salts oforganic acids. Such acids include formates, acetates, or heavieralkylcarboxylic acids such as oleates or naphthenates. Other organicacids which can be used include alkylsulfonic or arylsulfonic acids.

[0066] Particularly desirable complexes for the hydroformylation of thehigher olefins of this invention are the carbonyl compounds of themetals mentioned, as well as those containing amines, triorganicderivatives of phosphorous, arsenic or antimony, the respective oxidesof these derivatives, optionally functionalized to make them soluble inphases that under certain conditions can be separated from the organicreactor liquid.

[0067] Hydroformylation is desirably carried out at a temperatureranging from about 40° C. to about 220° C. Preferred is a temperatureranging from about 80° C. to about 200° C.; particularly about 90° C. toabout 180° C.

[0068] Hydroformylation can be carried out at conventionalhydroformylation pressure ranges. In general, hydroformylation isacceptable at a pressure range of from about 1 to about 400 bar gauge.Medium and high pressure ranges are preferred ranges. In general, mediumand high pressure ranges are considered to be in the range of about 40to about 400 bar gauge, more specifically in the range of about 50 toabout 320 bar gauge. Within these general pressure ranges CO-ligandedcatalyst processes are particularly useful.

[0069] A high pressure range is generally considered in the range ofabout 175 to about 400 bar gauge, more desirably about 190 to about 310bar gauge. CO-liganged rhodium and cobalt catalyst processes areparticularly useful in these high pressure ranges.

[0070] A medium pressure range is generally considered to be in therange of about 40 to about 175 bar gauge, more desirably about 50 toabout 150 bar gauge, and with certain catalysts it is desirable to bewithin a range of from about 60 to about 90 bar gauge. As an example, atriphenylphosphineoxide (TPPO)-liganded rhodium catalyst is particularlydesirable in the range of from about 50 to about 150 bar guage. Asanother example, a trialkylphosphine-liganded cobalt catalyst isparticularly desirable in the range of from about 60 to about 90 bargauge.

[0071] Hydroformylation can also be carried out in low pressure ranges.In general, the low pressure range will be in the range of from about 5to about 50 bar gauge, although a pressure range of from about 20 toabout 30 bar gauge is particularly useful. An example of ahydroformylation catalyst which is particularly useful in the lowpressure range is phosphine-liganded rhodium, more particularlytriphenylphosphine-liganded rhodium.

[0072] Other hydroformylation catalysts can be used within the pressureranges described. Such catalysts are described in Kirk-Othmer, 4^(th)Edition, Volume 17, “Oxo Process,” pages 902-919 and Ullman'sEncyclopedia of Industrial Chemistry, 5^(th) Edition, Volume A18, “OxoSynthesis,” pages 321-327, the detailed descriptions of each beingincorporated herein by reference.

[0073] It is desirable in some instances that hydroformylation becarried out at a carbon monoxide partial pressure not greater than about50% of the total pressure. The proportions of carbon monoxide andhydrogen used in the hydroformylation or oxo reactor at the foregoingpressures are desirably maintained as follows: CO from about 1 to about50 mol %, preferably from about 1 to about 35 mol %; and H₂ from about 1to about 98 mol %, preferably from about 10 to about 90 mol %.

[0074] The hydroformylation reaction is conducted in a batch modeaccording to one embodiment. Alternatively, the hydroformylationreaction can occur on a continuous basis. In a continuous mode, aresidence time of up to 4 hours is useful. If a plurality of reactors isemployed, a residence time as short as 1 minute is advantageous.Alternatively a residence time is in the range of from about ½ to about2 hours is useful.

[0075] Since the hydroformylation process of the invention takes placein the liquid phase and the reactants are gaseous compounds, a highcontact surface area between the gas and liquid phases is desirable toavoid mass transfer limitations. A high contact surface area between thecatalyst solution and the gas phase is obtainable in a variety of ways.For example and without limitation, contact surface area between thegaseous reactants and the liquid phase is obtained by stirring in abatch autoclave operation. In a continuous operation, the olefin feedstream of one embodiment is contacted with catalyst solution in, forexample, a continuous-flow stirred autoclave where the feed isintroduced and dispersed at the bottom of the vessel, preferably througha perforated inlet. Good contact between the catalyst and the gas feedis obtainable by dispersing a solution of the catalyst on a high surfacearea support. Such a technique is commonly referred to as supportedliquid phase catalysis. The catalyst is provided as part of a permeablegel.

[0076] The hydroformylation reaction is performed in a single reactoraccording to one embodiment. Examples of suitable reactors are found inU.S. Pat. Nos. 4,287,369 and 4,287,370 (Davy/UCC); U.S. Pat. No.4,322,564 (Mitsubishi); U.S. Pat. No. 4,479,012 and EP-A-114,611 (bothBASF); EP-A-103,810 and EP-A144,745 (both Hoechst/Ruhrchemie); and U.S.Pat. No. 5,763,678 (Exxon). Two or more reactor vessels or reactorschemes configured in parallel are used in another embodiment. Inaddition, a plug flow reactor design, optionally with partial liquidproduct backmixing, provides an efficient use of reactor volume.

[0077] It is preferred, according to one embodiment, that thehydroformylation reaction be carried out in more than one reaction zoneor vessel in series. Suitable reactor configurations are disclosed, forexample, by Fowler et al in British Patent Specification No. 1,387,657,by Bunning et al in U.S. Pat. No. 4,593,127, by Miyazawa et al in U.S.Pat. No. 5,105,018, by Unruh et al in U.S. Pat. No. 5,367,106. and byBeckers et al. in U.S. Pat. No. 5,763,678. Examples of individualhydroformylation reactors can of the standard types described by Denbighand Turner in Chemical Reactor Theory ISBN 0 521 07971 3, by Perry et alin Chemical Engineers' Handbook ISBN 0-07-085547-1 or any more recenteditions, e.g., a continuous stirred tank or a plug flow reactor withadequate contact of the gas and the liquid flowing through the reactor.Advantageously these plug flow reactor designs or configurations includeways of partial backmixing of the reactor product liquid, as explained,for example, by Elliehausen et al in EP-A-3,985 and in DE 3,220,858.

[0078] Hydroformylated products have utility as intermediates in themanufacture of numerous commercially important chemicals, with theinvention further providing processes in which hydroformylation isfollowed by reactions producing such chemicals. The reaction productswill typically be a mixture of oxygenated compounds, since the higherolefin components used to make the products will generally include amixture of components. The higher olefin components are generally amixture of components, because the olefin feed stream that is used tomake the oligomeric olefin product will generally include a mixture ofolefins. However, the resulting hydroformylation product stream willgenerally be higher in linearity as a result of the high degree oflinearity of the oligomeric olefin and olefin compositions used upstreamof the hydroformylation reaction process.

[0079] Either in their pure form, or as part of the mixture in thehydroformylation product, aldehydes which are produced are optionallyaldolized, a term which includes the dehydration of the aldol condensateto form an unsaturated aldehyde. This aldolization can be performed withthe other aldehydes present in the stream, or with aldehydes that wereprepared separately and are added to the original aldehyde orhydroformylation product stream.

[0080] Aldol product is optionally hydrogenated to the correspondingalcohol mixture. If desired, the unsaturated aldehyde mixture fromaldolization can be selectively hydrogenated to the saturated aldehydemixture. Any of the saturated aldehyde mixtures, either as made byhydroformylation or by selective hydrogenation of an aldol product, canhave special value when they are oxidized to their correspondingcarboxylic acids, or condensed with formaldehyde to polyols, or withammonia to imines which can be hydrogenated to amines. The acids andpolyols are valuable intermediates for esters, polyol esters, metalsalts, amides, chlorides, peroxides, and again for imines and amines.

[0081] In another embodiment of the invention, the hydroformylationproducts of this invention are optionally hydrogenated to form saturatedalcohols. Formation of a saturated alcohol may be carried out, ifdesired, in two stages through a saturated aldehyde, or in a singlestage to the saturated alcohol, in which case it is desirable to form asaturated aldehyde as an intermediate. The alcohols are then optionallyesterified, etherified, or formed into acetals or carbonates, which canbe used as plasticizers, surfactants or synthetic lubricants.

[0082] The esters and ethers of the invention, or produced by theprocess of the invention, are suitable for use as solvents, paintcoalescers, plasticizers, adhesives, surfactants, viscosity indeximprovers, synthetic lubricants, flame retardants, lubricant components,anti-wear agents, hydraulic fluids, cetane improvers, drilling fluids,thermoplastic and textile processing aids, polymer, especially vinylchloride polymer, stabilizers, polymerizable monomers and fragrances.

[0083] Esterification is accomplished by reacting the alcohols of thisinvention with acids or anhydrides. The reaction process desirably takesadvantage of conventional processes. In these conventional processes, itis desirable to react the alcohols and acids at elevated temperaturesand pressures, and to drive the reaction toward completion by removingwater that is produced as a by-product.

[0084] Catalysts may be employed in the esterification reaction.Suitable catalysts include, for example, titanium containing catalysts,e.g., a tetraalkyl titanate, in particular tetra-iso-propyl ortetraoctyl ortho titanate, or sulphonic acid containing catalysts, e.g.,p-toluene sulphonic acid or methylsulphonic acid.

[0085] Catalyst present in the esterification reaction product may beremoved by alkali treatment and water washing. Advantageously, thealcohol is used in slight, e.g., from 10 to 25%, molar excess relativeto the number of acid groups in the acid.

[0086] The acid of the ester may be inorganic or organic; if the latter,a carboxylic acid is preferred. Aromatic acids are preferred forplasticizer manufacture, although aliphatic acids are also employed.Additional examples of acids include, acetic, propionic, valeric,isovaleric, n-heptanoic, n-octanoic, n-decanoic, neodecanoic, lauric,stearic, iso-stearic, oleic, erucic, succinic, phthalic(1,2-benzenedicarboxylic), isophthalic, terephthalic, adipic, fumaric,azelaic, 2-ethylhexanoic, 3,5,5-trimethylhexanoic, 2-methylpentanoic,2,4-dimethylheptanoic, 2,4,6-trimethylnonanoic, sebacic, trimellitic,pyromellitic, acrylic, methacrylic, tall oil, naphthenic andnaphthalene-type acids, carbonic, nitric, sulphuric, phosphoric andphosphorous and their thio-analogous, acids and C₆ to C₁₃ oxo and neoacids. The esters of the C₉ and especially the C₁₂ alcohols with oxo andneo acids are especially useful as drilling fluids and powertransmission fluids. Phosphate esters are particularly desirable asflame retardants; while phosphite esters provide vinyl chloride polymerstabilizers.

[0087] Esters with monobasic and dibasic acids are preferred forlubricants and lubricant components. Advantageously the resulting esterscontain from 15 to 40 carbon atoms. Adipates, azelates, and phthalatesare especially preferred for lubricant manufacture. Esters withunsaturated carboxylic acids, e.g., with acrylic and methacrylic acid,provide polymerizable monomers, suitable as sole or co-monomer inthermoplastics manufacture, or in polymers used in or as adhesives, VIimprovers, and coating resins.

[0088] The esters of the invention may be used as a plasticizer fornumerous polymers. Examples include cellulose acetate; homo- andcopolymers of aromatic vinyl compounds e.g., styrene, or of vinyl esterswith carboxylic acids e.g., ethylene/vinyl acetate copolymers;halogen-containing polymers, especially vinyl chloride homo- andcopolymers, more especially those copolymers with vinyl esters ofcarboxylic acids, esters of unsaturated carboxylic acids e.g.,methacrylates, and/or olefins; nitrile rubbers; and post-chlorinatedvinyl chloride polymers. Poly(vinyl chloride) is of particular interest.

[0089] The proportion of plasticizer ester to polymer may vary withinwide limits. A desirable range is from about 10 to about 200 parts byweight per 100 parts of polymer, preferably from about 20 to about 100parts per 100 parts of polymer.

[0090] The esters of the invention may be used alone as plasticizer, orin admixture with one another, or in admixture with other plasticizers,for example, dibutyl, dipentyl, dihexyl, diheptyl, dioctyl, dinonyl,didecyl, diundecyl, didodecyl, ditridecyl phthalates, trimellitates oradipates, or butyl benzyl phthalate, or mixtures thereof. They may also,or instead, be used with a secondary plasticizer, e.g., a chlorinatedparaffin, Texanol isobutyrate, or a processing oil. If used inadmixture, it is the total proportion of plasticizer that isadvantageously within the ranges given above.

[0091] The plasticized polymeric compositions of the invention may bemade up in numerous forms and have various end-uses. For example, theymay be in the form of a dryblend, a paste, or a plastisol, depending onthe grade of the resin employed. They may be used, for example, ascoatings, in dipping, spraying, injection or rotational molding,extrusion, or as self-supporting films and sheets, and may readily befoamed. End uses include flooring materials, wall coverings, moldedproducts, upholstery materials, leather substitutes, electricalinsulation, especially wire and cable, coated fabrics, toys, andautomobile parts.

[0092] The invention also provides a composition comprising an ester ofthe invention and a refrigerant, especially a fluorocarbon refrigerant,and more especially HFC 32 (difluoromethane) or HFC 134a(1,1,1,2-tetrafluoroethane). More especially, the invention providessuch a composition also comprising at least one of a hydrolyticstability enhancer, e.g., a hindered phenol or an aromatic amine, anantioxidant, corrosion inhibitor, and a metal deactivator.

[0093] Under circumstances where the olefin feed is ultimately derivedfrom a low-value feedstock like natural gas, i.e., in cases wheremethane from natural gas is converted to methanol and the methanol toolefin, the products or product mixtures may have value as liquidtransportable fuels, optionally after dehydration to the olefin, and ifdesired hydrogenation to a paraffin or paraffinic mixture. Particularlyvaluable compositions produce according to this invention are isononylalcohol mixtures, made by hydroformylation and hydrogenation of octenemixtures. The invention also provides a valuable process for themanufacture of isooctanoic acid, wherein the aldehyde fromhydroformylation of a heptene mixture is separated from thehydroformylation product and subsequently oxidized.

[0094] Having now fully described this invention, it will be appreciatedby those skilled in the art that the invention can be performed within awide range of parameters within what is claimed, without departing fromthe spirit and scope of the invention.

What is claimed is:
 1. A method of converting an oxygenate to adimerized or oligomerized olefin product, comprising: contactingoxygenate with a silicoaluminophosphate molecular sieve catalyst to forman olefin product; separating a propylene, butylene or pentylenecontaining olefin stream from the olefin product, wherein the separatedolefin stream comprises at least 50 wt. % propylene, butylene,pentylene, or a combination thereof, and the separated olefin streamcontains not greater than 1 ppm by weight sulfur calculated on an atomicbasis, and 0.5 to 10 wt. % isoolefin; and contacting the separatedolefin stream with a nickel based oligomerization catalyst to form adimer or oligomer product.
 2. The method of claim 1, wherein theseparated olefin stream comprises not greater than 1 ppm by weightnitrogen.
 3. The method of claim 1, wherein the separated olefin streamcomprises not greater than 0.5 ppm by weight chlorine.
 4. The method ofclaim 1, wherein the separated olefin stream comprises from 1 to 8 wt. %isoolefin.
 5. The method of claim 4, wherein the separated olefin streamcomprises from 2 to 6 wt. % isoolefin.
 6. The method of claim 1, 4 or 5,wherein the isoolefin is isobutylene.
 7. The method of claim 1, whereinthe silicoaluminophosphate is SAPO-34, SAPO-18, or a combinationthereof.
 8. The method of claim 1, wherein the silicoaluminophosphate isan intergrowth of SAPO-34 and SAPO-18 or ALPO-18.
 9. The method of claim1, further comprising recovering the dimer or oligomer product andcontacting the product with a hydroformylating catalyst to form ahydroformylated product.
 10. The method of claim 9, further comprisingconverting the hydroformylated product to an acid or alcohol.
 11. Themethod of claim 10, further comprising converting the acid or alcohol toan ester.
 12. The method of claim 11, further comprising adding theester to a polymer composition.
 13. A method of converting an oxygenateto a dimerized or oligomerized olefin product, comprising: contactingoxygenate with a SAPO-34 molecular sieve catalyst to form an olefinproduct; separating a propylene, butylene, or pentylene containingolefin stream from the olefin product, wherein the separated olefinstream comprises at least 50 wt. % propylene, butylene, pentylene, or acombination thereof, and the separated olefin stream contains notgreater than 1 ppm by weight sulfur, not greater than 1 ppm by weightnitrogen, and not greater than 0.5 ppm by weight chlorine, eachcalculated on an atomic basis, and 0.5 to 10 wt. % isoolefin; andcontacting the separated olefin stream with a nickel basedoligomerization catalyst to form a dimer or oligomer product.
 14. Themethod of claim 13, wherein the SAPO-34 catalyst further comprisesSAPO-18 or ALPO-18.
 15. The method of claim 13, wherein the SAPO-34catalyst is an intergrowth of SAPO-34 and SAPO-18 ALPO-18.
 16. Themethod of claim 13, wherein the separated olefin stream comprises from 1to 8 wt. % isoolefin.
 17. The method of claim 1, wherein the separatedolefin stream comprises from 2 to 6 wt. % isoolefin.
 18. The method ofclaim 13, 16, or 17, wherein the isoolefin is isobutylene.
 19. An olefincomposition, comprising at least 50 wt. % propylene, butylene, pentyleneor a combination thereof, and containing not greater than 1 ppm byweight sulfur, not greater than 1 ppm by weight nitrogen, and notgreater than 0.5 ppm by weight chlorine, each calculated on an atomicbasis, and 0.5 to 10 wt. % isoolefin.
 20. The olefin composition ofclaim 19, wherein the olefin composition comprises from 1 to 8 wt. %isoolefin.
 21. The olefin composition of claim 19, wherein the olefincomposition comprises from 2 to 6 wt. % isoolefin.
 22. The olefincomposition of claim 19, 20, or 21, wherein the isoolefin isisobutylene.
 23. A method of converting an oxygenate to ahydroformylated product, comprising: contacting oxygenate with asilicoaluminophosphate molecular sieve catalyst to form an olefinproduct; separating a propylene, butylene or pentylene containing olefinstream from the olefin product, wherein the separated olefin streamcomprises at least 50 wt. % propylene, butylene, pentylene, or acombination thereof, and the separated olefin stream contains notgreater than 1 ppm by weight sulfur calculated on an atomic basis, and0.5 to 10 wt. % isoolefin; contacting the separated olefin stream with anickel based oligomerization catalyst to form a dimer or oligomerproduct; and contacting the dimer or oligomer product with ahydroformylating catalyst to form a hydroformylated product.
 24. Themethod of claim 23, further comprising converting the hydroformylatedproduct to an acid or alcohol.
 25. The method of claim 24, furthercomprising converting the acid or alcohol to an ester.
 26. The method ofclaim 25, further comprising adding the ester to a polymer composition.